On Thursday, April 18, 2013 09:57:16 PM Elvis Dowson wrote: > On Apr 18, 2013, at 8:51 PM, "Robert P. J. Day" <rpj...@crashcourse.ca> wrote: > > On Thu, 18 Apr 2013, Enrico Scholz wrote: > >> "Robert P. J. Day" <rpjday-L09J2beyid0N/h6p543...@public.gmane.org> > >> > >> writes: > >>> Have default, commented values for parallelism reflect quad-core > >>> hosts. > >> > >> fwiw, I use > >> > >> PARALLEL_MAKE = "\ > >> > >> -j ${@int(os.sysconf(os.sysconf_names['SC_NPROCESSORS_ONLN'])) * 2} \ > >> -l ${@int(os.sysconf(os.sysconf_names['SC_NPROCESSORS_ONLN'])) * > >> 150/100} \ > >> > >> " > >> > >> BB_NUMBER_THREADS ?= "\ > >> > >> ${@int(os.sysconf(os.sysconf_names['SC_NPROCESSORS_ONLN'])) * 150/100}" > >> > >> which adjusts parallelism automatically. > >> > > i'd be perfectly fine with that, too, if someone wants to put that > > > > in instead. > > I've noticed that on a quad-core machine (i7) the best setting is to leave > it at 6 for BB_NUMBER_THREADS and PARALLEL_MAKE. maybe we need consider the hyper-threading.
CPU_PROC_NUM="`grep "^processor" /proc/cpuinfo | sort -u | wc -l`" CPU_CORE_NUM="`grep "^core id" /proc/cpuinfo | sort -u | wc -l`" > 8, 16, etc don't have any discernable impact, perhaps save 30 to 40 seconds > off a build. The 3.5Ghz standard CPU frequency can be over-clocked to as > high as 4.5GHz, but I tested it out at 4.2Ghz and 3.8Ghz, and the > difference was only 2 to 3 minutes between 3.8GHz and 4.2GHz over-clocked, > so I currently leave it at 3.8GHz over-clocked. > > I'm using two SSDs in a RAID 0 striped configuration, and build times is > around 22 minutes for a Zynq-7-ZC702 build for core-image-minimal. > > Elvis Dowson > _______________________________________________ > Openembedded-core mailing list > Openembedded-core@lists.openembedded.org > http://lists.linuxtogo.org/cgi-bin/mailman/listinfo/openembedded-core -- Nanjing Jilong Yi Qingliang niqingliang2...@gmail.com _______________________________________________ Openembedded-core mailing list Openembedded-core@lists.openembedded.org http://lists.linuxtogo.org/cgi-bin/mailman/listinfo/openembedded-core